Electrical energy storage devices such as supercapacitors or lithium batteries are widely used in electric and hybrid electric vehicles, portable electronic devices, and stationary electrical energy storage. The electrodes of an electrical energy storage apparatus are typically constructed to have large surface areas in order to achieve high energy capacity. In supercapacitors, this can be accomplished by spiral-winding long conductive foils separated by thin insulating plastic or paper materials, and/or by applying electrodes made out of or coated with a material having special structures or compositions.